This invention relates to modular sprinkler devices and, more specifically, the invention relates to an improved positive latching cap for a modular sprinkler which prevents separation of the cap (and sprinkler components attached thereto) from the sprinkler body during use.
Moving irrigation systems, such as conventional pivot move and lateral move systems, are known to incorporate conduit truss span assemblies at a plurality of drop tubes by which a corresponding number of spray heads incorporating rotatable distributors (also referred to as rotor plates or spinners), fixed spray plates, or bubbler devices are suspended so as to be located in close proximity to crops or other plants.
There is currently in use a modular spray head which includes a sprinkler body and a cap assembly including a stream distributor (for example, a rotor plate or a fixed spray head) which is designed for quick assembly and disassembly from the sprinkler body. The cap assembly is secured to the sprinkler body by a conventional screw thread arrangement in combination with a locking mechanism where a plurality of vertically extending projections on the cap (extending from the cap surface by no more than about 1/16 inch) engage a corresponding plurality of notches formed on the cap mounting ring when the cap reaches the full extent of its rotational movement relative to the body during threading. To disassemble the cap, the latter is simply rotated counterclockwise with sufficient force to disengage the projections from the notches.
The above described prior arrangement may experience problems in the field, however, by reason of the detachment of the cap and rotor plate (or fixed spray plate) from the sprinkler body, rendering the spray head substantially inoperative. The detachment problem is caused by brushing engagement of the spray head with crops (such as corn stalks) as the system moves through a field. As a result, the known locking mechanism is insufficient to withstand the rigors of use in its intended environment. Similar detachment problems may be experienced with the sprinkler devices associated with known drag socks and drag hoses which are pulled along the ground.
An improved locking arrangement between a cap assembly and a sprinkler body is disclosed in commonly owned U.S. Pat. No. 5,224,653. In that application, the sprinkler body is formed with an upwardly extending frusto-conical portion which supports, by way of three equally circumferentially spaced posts, an annular cap mounting ring. This ring has a substantially vertical exterior surface formed with a plurality of discontinuous thread ramps separated by a plurality of circumferentially spaced gaps. Each ramp extends circumferentially from its free or starting end partially about the circumference of the ring and downwardly to a termination point defined by one of the respective posts. The interior of the annular ring, also formed as a vertical surface, is formed with a plurality of equally circumferentially spaced wedge-shaped detents which are adapted to cooperate with a mating latching element formed on the cap.
The cap portion of the sprinkler assembly is generally circular in shape and includes a top wall and an outer depending skirt portion. The top wall is provided with a centrally located aperture for supporting a rotor plate. The outer annular surface of the skirt is provided at its lower edge with three, equally circumferentially spaced, radially inwardly directed tabs which are adapted to pass simultaneously through the correspondingly located gaps between the thread ramps on the annular mounting ring. The cap is placed on the ring with the components oriented so that the tabs are aligned with the gaps. Once the tabs have been pushed downward through the gaps, clockwise rotation of the cap will cause the latter to be pulled downwardly onto the mounting ring by the thread ramps.
The cap is also formed with a radial thumb press which includes a pushbutton extending radially outwardly from the cap skirt and connected to the cap skirt by means of a pair of thin, circumferentially extending webs which provide the button with both radial and axial flexibility. The thumb press is integrally connected to a latching member which extends radially inwardly of the button and which is accommodated within a notch provided in the cap top wall. The underside of the latching member includes a wedge-shaped latching element which is substantially similar in shape to the wedge-shaped detents provided on the interior surface of the annular mounting ring.
The arrangement is such that after placement of the cap on the sprinkler body and upon clockwise rotation of the cap relative to the body, the wedge-shaped latching element will be resiliently biased upwardly and/or radially outwardly to allow the element to ride along the upper edge of the annular mounting ring. When the latching element finds the next adjacent wedge-shaped detent, it is resiliently pushed into the detent to thereby releasably lock the cap to the sprinkler body. The cap may be removed by pushing the thumb press button radially inwardly to release the latching element from the detent, thereby permitting counterclockwise rotation of the cap relative to the body.
In this invention, a further improved positive latching cap is provided which provides a secure connection between the cap and the sprinkler body, but which also permits quick and easy removal of the cap.
More specifically, the modular sprinkler in the exemplary embodiment includes a sprinkler body portion, a removable cap assembly, a quick change nozzle and an adapter for connecting the modular sprinkler to a drop tube, hose, or other conduit connected to a water source. The cap assembly include sa distribution plate or rotor plate (or a fixed spray head) which redirects a stream issuing from the nozzle in a substantially radial direction. The rotation of the rotor plate is controlled by a viscous fluid brake or dampener mechanism which is frictionally held within a centrally oriented hub portion of the cap assembly. The sprinkler body supports an annular cap mounting ring in a manner similar to that described in the '448 application, but the mounting ring, and the associated cap component of the cap assembly incorporate a new positive latching mechanism as described further herein.
The annular cap mounting ring of the sprinkler body includes a vertical wall having an upper edge and three radially outwardly projecting lugs or tabs which are contiguous with that upper edge. At centrally located positions between each of the radially outwardly projecting tabs, the cap mounting ring wall incorporates resilient spring areas, each of which is defined by an elongated slot formed in the wall. These spring areas extend slightly above the remaining portions of the upper edge of the wall. The resulting, relatively thin webs defined by the upper edge of the wall and by the elongated slots, are thus provided with a measure of resilient flexibility which allows them to act in the manner of spring in vertical directions.
The cap component of the cap assembly is formed with a top wall and an annular, depending skirt portion. The top wall is formed with a centrally located aperture through which the previously described viscous brake or dampener extends. The brake mechanism is frictionally held by a plurality of spring fingers which extend upwardly as part of a central hub sleeve in which the brake mechanism is received. The underside of the top wall of the cap component is provided with three equally spaced lugs which project downwardly toward the sprinkler body. In addition, the interior surface of the depending skirt is formed with three equally circumferentially spaced wedge locks which project radially inwardly and which also extend circumferentially. Each wedge lock includes a wedge-like ramp surface and a horizontal land which has a height slightly less than the uppermost point of the ramp surface.
In order to assemble the cap assembly to the sprinkler body, the cap assembly is positioned onto the body in such a way that the wedge locks are able to clear the tabs on the annular cap mounting ring. The cap assembly may then be rotated in a clockwise direction such that the tabs on the cap mounting ring pull the cap assembly downwardly by reason of the sliding engagement of the tabs relative to the wedge-like ramp surfaces of the wedge locks. As the cap assembly is pulled down, the projecting lugs on the underside of the top wall engage the raised portions of the resilient spring areas to, in effect, exert an upward bias on the cap assembly relative to the body portion. The cap assembly continues to be rotated until the tabs have passed over the uppermost edges of the respective wedge-like ramp surfaces, and have seated themselves in the land areas of the wedge locks. Because these land areas are at a height slightly less than the uppermost edges of the wedge-like ramp surfaces (thereby creating a step or shoulder), when the tabs seat in the lands, the resistive spring force exerted by the resilient spring areas on the cap assembly will be relieved. In this releasably locked position, the fully engaged seating between the tabs and the lands will prevent inadvertent or accidental disassembly of the cap assembly from the sprinkler body during use.
In order to remove the cap assembly, one need only press downwardly on the cap assembly relative to the body (and against the resistive force exerted by the resilient spring areas), so as to enable the tabs to clear the shoulders between the wedge-like ramp surfaces and the lands. This then enables the user to rotate the cap assembly in a counterclockwise direction until the positive latching device or wedge locks are moved to locations circumferentially spaced from the tabs. At this point, the user can simply lift the cap assembly upwardly away from the sprinkler body.
Thus, in accordance with one aspect of the invention, there is provided a modular sprinkler assembly comprising a sprinkler body including an annular cap supporting ring and a nozzle for emitting a liquid stream to atmosphere, and a cap assembly removably secured to the cap supporting ring, the cap assembly including a cap supporting a stream distributor, the cap having a top wall and an annular depending skirt, an interior surface of the skirt having at least one latch device formed thereon, the latch device including a wedge-shaped surface portion and a land portion, and wherein the cap supporting ring has at least one radially extending tab adapted to ride on the wedge-shaped surface portion and to seat on the land portion upon rotation of the cap relative to the sprinkler body.
In accordance with another aspect, the invention provides a modular sprinkler assembly comprising a sprinkler body having a nozzle therein for emitting a stream in a direction substantially coincident with a longitudinal axis of the sprinkler body, the sprinkler body also having a supporting ring located downstream of the nozzle; and a cap assembly removably secured on the mounting ring, the cap assembly including a cap having a top wall and a depending skirt, the top wall supporting at least one stream distributor in proximity to the nozzle; the mounting ring and the cap having first and second means, respectively, for removably securing the cap assembly to the mounting ring, the second means including at least one wedge lock extending partially about the mounting ring, the wedge lock including a wedge surface and an adjacent land for cooperating engagement with the first means.
In still another aspect, the invention provides a modular sprinkler assembly comprising a sprinkler body including a substantially vertical annular cap supporting ring and a nozzle for emitting a liquid stream to atmosphere; and a cap assembly removably secured to the cap supporting ring, the cap having a top wall and upper and lower skirt portions extending in opposite directions from the top wall, a first stream distributor mounted in said top wall and facing in one direction, and a second stream distributor mounted on the top wall and facing in a direction opposite to the one direction.
It will be appreciated from the above general description, that the positive latching cap assembly in accordance with this invention provides secure releasably locked engagement between the cap assembly and the sprinkler body portion, while at the same time, permitting easy removal of the cap assembly.
Other objects and advantages of the invention will become apparent from the detailed description which follows.